Obesity and carbohydrate intolerance are common amongst the Pima Indians. It is possible that the development of obesity may in part be determined by the rates of gastric emptying. Furthermore, peptic ulcer disease is known to be low in the Pima Indian population, but increasing. We have also recently demonstrated that postprandial serum gastrin levels in diabetic Pima Indians are high. For the above reasons we plan to determine both gastric secretory and gastric emptying rates in Pima Indian subjects over a range of obesity, with and without diabetes.